Prostate cancer is the most common malignancy in males and, despite a marked improvement in diagnostic techniques, a not small percentage of prostate tumours is still diagnosed in advanced stage. It is now clear that prostate cancer passes through distinct phases during its natural history, starting from an initial phase, in which the disease has a locoregional extent, until a very late phase when it becomes refractory to hormone therapy.
It is important to distinguish between local disease, in which tumor may be considered localized in the gland and a systemic disease characterized by high tumor burden and/or dissemination of circulating tumour cells.
All the prostate cancers, at first diagnosis, are characterized by high sensitivity to the androgen deprivation therapy (ADT); however, during the natural history, after a variable period, they become castration resistant. In the past, few therapy options were available for castration resistant prostate cancer, while at present much more approaches can be employed, both hormone-based therapies and chemotherapy regimens. Hypercastration agents are defined as drugs capable to target the androgenandrogen receptor axis even in castrate resistant conditions. Abiraterone and enzalutamide are the only two hypercastration agents available for clinical use.
Osteoclast targeted agents, such as zoledronic acid and denosumab can always been employed, but their use should be limited to the castrate resistant setting.
The optimal understanding of all phases characterizing the natural history of prostate cancer may certainly be useful for the selection of the best therapeutic options in prostate cancer.
Keywords: Prostate cancer, androgen deprivation therapy, hypercastration, natural history, metastatic castration resistant prostate cancer, bone metastasis.